A215897 - OEIS

A215897

a(n) = A215723(n) / 2^(n-1).

1, 0, 1, 2, 3, 4, 8, 18, 27, 44, 267, 1024, 3645, 6144, 23859, 50176, 187377, 531468, 3302697, 10616832, 39337984, 102546588, 568833245, 3073593600, 8721488875, 32998447572, 164855413835, 572108938470, 2490252810073, 10831449635712, 68045615234375, 282773291271138, 1592413932070703, 5234078743146888

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OFFSET

1,4

COMMENTS

A215723(n) is divisible by 2^(n-1), indeed the determinant of any n X n sign matrix is divisible by 2^(n-1). Proof: subtract the first row from other rows, the result is all rows except for the first are divisible by 2, hence by using expansion by minors proof follows. (Warren D. Smith on the math-fun mailing list, Aug 18 2012)

LINKS

Richard P. Brent, Table of n, a(n) for n = 1..52

Richard P. Brent and Adam B. Yedidia, Computation of maximal determinants of binary circulant matrices, arXiv:1801.00399 [math.CO], 2018.

R. P. Brent and A. Yedidia, Computation of maximal determinants of binary circulant matrices, Journal of Integer Sequences, 21 (2018), article 18.5.6.

Index entries for sequences related to maximal determinants

FORMULA

a(n) = A215723(n) / 2^(n-1).

CROSSREFS

Cf. A215723 (Maximum determinant of an n X n circulant (1,-1)-matrix).

Sequence in context: A372100 A296109 A102276 * A276673 A282815 A339630

Adjacent sequences: A215894 A215895 A215896 * A215898 A215899 A215900

KEYWORD